Low-dose Dobutamine Stress Echocardiography Research Articles

Low‐Dose Dobutamine Stress Echocardiography to Predict Reversibility of Mitral Regurgitation with CABG

The optimal management of moderate (grade 2-3+) ischemic mitral regurgitation (MR) in patients undergoing coronary artery bypass grafting (CABG) remains controversial. While CABG alone can reverse regurgitation in some patients with moderate MR, adjunctive mitral repair may be necessary in others. We performed low-dose dobutamine stress echocardiography (DSE) in 60 patients with moderate MR who were about to undergo CABG. Group I, 25 patients who demonstrated reduction in MR during DSE, had CABG alone. Group II, 35 patients in whom MR was unchanged during DSE, had mitral valve repair as well as CABG. MR was reduced postoperatively in both groups (P < 0.0001). Postoperative ejection fraction in Group I (12.2%) improved more than that in Group II (9.3%) (P < 0.01). We conclude that CABG alone may be sufficient to correct moderate MR when MR is reduced during DSE.

Quantification of valvular lesions in patients with left ventricular dysfunction

Echocardiography is the preferred method for assessment of aortic and mitral valvular lesions. The pressure gradient in aortic stenosis may be misleading in patients with poor left ventricular function. Aortic valve area planimetry by transesophageal echocardiography results in a flow independent anatomic measurement. Low-dose dobutamine stress echocardiography provides important prognostic information. Quantitative Doppler echocardiography allows accurate assessment of mitral regurgitation severity. However, the definition of what is severe mitral regurgitation is different in patients with left ventricular dysfunction.

Early reduction in left ventricular contractile reserve detected by dobutamine stress echo predicts high-dose chemotherapy-induced cardiac toxicity

Background High-dose chemotherapy (HDC) is utilized in high-risk cancer patients. This type of treatment may induce cardiac toxicity which becomes clinically evident weeks or months after HDC. Hence, the possibility of early identification of patients who will develop cardiac impairment is strategic for its clinical implications. The aim of this study was to identify possible early changes of left ventricular contractile reserve (LVCR) in cancer patients undergoing HDC, as well as to evaluate the relevance of such changes as predictors of chemotherapy-induced cardiotoxicity. Methods In forty-nine female patients scheduled for HDC, due to poor-prognosis breast cancer, dobutamine stress echocardiography (DSE) was performed, before each of the three HDC cycles (C1, C2, C3), and 1, 4, and 7 months after the end of chemotherapy. According to rest left ventricular ejection fraction (LVEF) evaluated within 18 months after HDC (f-LVEF), patients were allocated to Group A (LVEF < 50% and > 10 absolute units reduction) and to Group B (LVEF ≥ 50%). Results Rest LVEF didn't show any significant difference between the two groups except at f-LVEF. Peak LVEF and LVCR significantly decreased in Group A only, starting from C3. At C3, a ≥ 5 units fall in LVCR was found to be predictive for f-LVEF drop below 50%. Conclusions In patients undergoing HDC, low-dose DSE allows the early identification of patients at a high risk of developing cardiac dysfunction.

The presence of contractile reserve has no predictive value for the evolution of left ventricular function following atrio-ventricular node ablation in patients with permanent atrial fibrillation

Transcatheter ablation of the atrio-ventricular (AV) node followed by ventricular pacing has been shown to improve symptoms and quality of life (QOL) of patients with permanent atrial fibrillation (AF). In a considerable number of patients, cardiac function deteriorates after AV node ablation. We aimed to determine whether the absence of contractile reserve assessed by low dose dobutamine stress echocardiography (LDDSE) could identify those patients whose left ventricular (LV) function deteriorates after AV node ablation. All 25 patients studied had permanent AF for at least 12 months. LVEF was determined 6 days and 3 months after AV node ablation by radionuclide ventriculography (RNV), at a paced rate of 80 beats/min. Deterioration in cardiac function was defined as a decrease in LVEF>5%. LDSE was performed in all patients before and after ablation. The presence of contractile reserve was defined as an improvement in regional function of >or=1 grade at low dose dobutamine in at least 4 segments. QOL measurements were taken using Minnesota, NHBP and MPWB questionnaires. LVEF showed no improvement in the overall group (52.8+/-11.1% vs. 51.8+/-9.8%, p=NS). QOL showed significant improvement in all questionnaires (Minnesota: 4.1+/-2.1 vs. 2.5+/-2, p=0.001; NHBP: 54.8+/-43.3 vs. 34.2+/-34.3, p=0.002; MPWB: 22.2+/-4.6 vs. 19.4+/-6.2, p=0.03). There was no significant difference in change of LVEF between patients with and without contractile reserve (-0.4+/-8.7 vs. 1.6+/-11.3, p=NS). However, patients with a preserved LVEF at baseline showed more frequently a reduced LVEF after AV node ablation (62.2+/-10.4% vs. 47.5+/-7.6%, p=0.001). (1) The absence of contractile reserve does not predict deterioration of cardiac function after AV node ablation. (2) AV node ablation results in a significant improvement in QOL, which is not necessarily associated with improvement of LVEF. (3) Higher baseline LVEF predicts deterioration of cardiac function. These data suggest that although AV node ablation is an excellent way of controlling symptoms, it should be avoided in patients with normal LV function.

Tissue velocity imaging during dobutamine stimulation for assessment of myocardial viability: Segmental analysis in patients after myocardial infarction

Background Dobutamine stress echocardiography (DSE) is an established method for the detection of viable myocardium, but evaluation of this method is subjective. Tissue velocity Imaging (TVI) allows quantitative analysis of regional myocardial wall motion by assessment of systolic myocardial velocities. The aim of this study was to evaluate the diagnostic value of DSE and TVI for detection of viable myocardium. Methods In 56 patients (58 ± 12 years) with previous myocardial infarction (130 ± 42 days, mean ejection fraction 42 ± 15%) low-dose DSE was combined with analysis of peak systolic myocardial velocities ( V peak) by TVI for assessment of myocardial viability. As reference served a follow-up echocardiography after successful revascularization (mean 91 ± 3 days). Results Of a total of 896 segments 200 showed abnormal wall motion (31 mildly hypokinetic, 50 severely hypokinetic, 115 akinetic, 4 dyskinetic). In 125 of these 200 segments regional improvement of regional wall motion was observed (62.5% viable). An increase of V peak > 1 cm/s during dobutamine stimulation allowed the identification of viable myocardium with a sensitivity of 82% and a specificity 82% (DSE: 77% and 80%). By receiver operating characteristic (ROC) curve analysis, a cut-off value of 1.0 cm/s was the best parameter to differ viable from nonviable myocardium (area under the curve 0.85; p < 0.01; 95% CI 0.79 to 0.90). Improvement of global ejection fraction after revascularization (47 ± 13%, p = 0.11) corresponded with three TVI viable segments with a sensitivity of 92% and a specificity of 89% ( p = 0.012). Conclusions TVI allows the identification of viable myocardium during dobutamine stimulation and enables a quantitative interpretation of DSE.

Cardioprotective effect of dexrazoxane during treatment with doxorubicin: A study using low‐dose dobutamine stress echocardiography

To assess the late cardioprotective effect of dexrazoxane associated with doxorubicin during treatment of osteosarcoma by means of low-dose dobutamine stress echocardiography (LDDSE) in non-relapsed asymptomatic children and teenagers. The study population included 58 patients with osteosarcoma divided in three groups, with equivalent age range, gender proportion and body surface area. Group I (21 patients, 14 males, 15 +/- 4 years) was analyzed before chemotherapy and considered the control group; Group II (19 patients, 11 males, 19.7 +/- 4 years) was treated with 348.4 +/- 18 mg/m2 of doxorubicin only and Group III (18 patients, 14 male, 16.8 +/- 5 years) treated with 396.5 +/- 55 mg/m2 of doxorubicin with dexrazoxane in the ratio 10:1. The patients were submitted to LDDSE (maximal dose 5 microg/kg/min). No major side effects were observed. Heart rate, blood pressure, left ventricular diameters, end systolic wall stress (ESWS), and other diastolic and systolic function indexes were assessed at rest conditions and during LDDSE and compared between the three groups. Group III received a doxorubicin dose significantly greater than Group II (P = 0.001). During LDDSE there were no significant changes in the diastolic function indexes in any of the groups, but there was a significant increase of systolic indexes and a decrease of ESWS in Group III compared to group II. There was no significant difference of any systolic functional parameters between Group I and III. Considering the ejection fraction (EF) at rest or at LDDSE, 13 patients (69.4%) in Group II and 5 patients (27.7%) in Group III were considered to have systolic dysfunction. (P = 0.02). Myocardial response to LDDSE in patients treated with doxorubicin and dexrazoxane was similar to patients without chemotherapy and better than those treated with doxorubicin only, suggesting less cardiotoxicity.

Detection of Functional Recovery Using Low‐Dose Dobutamine and Myocardial Contrast Echocardiography After Acute Myocardial Infarction Treated with Successful Thrombolytic Therapy

We studied the value of low-dose dobutamine stress echocardiography (LDDE) and myocardial contrast echocardiography (MCE) in early prediction of left ventricular functional recovery (LVFR) after acute myocardial infarction (AMI) treated with successful thrombolysis. LDDE and MCE using second-harmonic intermittent imaging were performed in first week after AMI. LVFR was defined as an absolute > or =5% increase in ejection fraction, from early to 6 months of follow-up by Technetium-99m-Sestamibi single-photon emission computed tomography. Out of 50 patients studied, 19 evolved with LVFR (group 1) and 31 without LVFR (group 2). Regional dysfunction was detected in 103 (37%) infarcted-related segments in group 1 and in 173 (63%) segments in group 2. Sensitivity, specificity, positive, and negative predictive values and accuracy for detecting LVFR by LDDE were 94.7% (18/19), 87.1% (27/31), 81.8% (18/22), 96.4% (27/28), and 90% (45/50), respectively, and by MCE were 94.7% (18/19), 51.6% (16/31), 54.5% (18/33), 94.1% (16/17), and 68% (34/50). In group 1, functional improvement was observed in 86.9% (53/61) of segments with contractile reserve by LDDE and in 65.8% (52/79) of segments with microvascular perfusion by MCE. In group 2, functional improvement was observed in 78.3% (18/23) of segments with contractile reserve by LDDE and in 25.5% (25/98) of segments with microvascular perfusion by MCE. All segments without perfusion by MCE evolved without functional recovery. LDDE was an accurate predictor of late left ventricular function recovery after AMI, while MCE was sensitive and has a high negative predictive value demonstrating that microvascular perfusion is essential for LVFR.

Left atrial systolic reserve in idiopathic vs. ischaemic‐dilated cardiomyopathy

There are studies indicating more pronounced left atrial (LA) systolic dysfunction at rest in idiopathic (IDDC) than in ischaemic-dilated cardiomyopathy (ISDC). It was hypothesized that the findings would be similar with regards LA systolic reserve. Twenty-six patients with IDDC, 28 with ISDC and 25 normal controls underwent low-dose dobutamine stress echocardiography (5-10 microg kg(-1) min(-1) IV). Left atrial volumes were echocardiographically determined at rest and during stress at the mitral valve opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp) and mitral valve closure (minimal, Vmin) from the apical 4- and 2-chamber views (biplane area-length method). Left atrial systolic function was assessed with the LA-active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp. Vmax at rest was similar in IDDC and ISDC and greater than in the controls (54.2 +/- 12 vs. 48.5 +/- 18 vs. 27.1 +/- 6.3 cm(3) m(-2), respectively, P < 0.001) and did not change with stress (53.9 +/- 13.8 vs. 46.9 +/- 16.2 vs. 25.8 +/- 5.9 cm(3) m(-2), P < 0.001). The ACTEV at rest was similar in IDDC and ISDC and greater than in the controls (8.6 +/- 3.5 vs. 9.7 +/- 2.9 vs. 6.1 +/- 2.2 cm(3) m(-2) P < 0.01), whereas during the dobutamine infusion it remained unaltered in IDDC (10.8 +/- 4.6 cm(3) m(-2), P = NS vs. rest) and increased in ISDC (11.8 +/- 3.3 cm(3) m(-2), P < 0.05) and the controls (13.1 +/- 3.2 cm(3) m(-2), P < 0.01). The ACTEF was lower in IDDC than ISDC and the controls at rest (20 +/- 10% vs. 33 +/- 8% vs. 36 +/- 10%, P < 0.01). Dobutamine infusion was associated with no significant increase in ACTEF in IDDC (25 +/- 12%, P = NS vs. rest), and with an increase in this variable in ISDC (39 +/- 10%, P < 0.05) and the controls (49 +/- 12%, P < 0.01). Dobutamine infusion is associated with an increase in LA ACTEV and fraction in ISDC and no significant change in these indices in IDDC. These findings indicate a reduced LA systolic reserve in IDDC.

Usefulness of low-dose dobutamine stress echocardiography for the evaluation of spontaneous recovery of stunned myocardium in patients with acute right ventricular infarction

Right ventricular (RV) infarction (RVI) is usually associated with severe RV global dysfunction representing predominantly stunned myocardium that may respond favorably to reperfusion. We assessed the efficacy of low-dose dobutamine stress echocardiography (DSE), performed early in the course of a reperfused RVI, to predict the recovery of RV systolic and diastolic function in 3 months, documenting the recovery of stunned myocardium. In all, 27 patients with acute, successfully thrombolyzed RVI comprised the study population. All patients underwent standard echocardiography at baseline and 3 months later for evaluation of RV systolic and diastolic function. At day 5 DSE was performed for evaluation of RV contractile reserve. Of the total number of segments analyzed, 69% were detected as stunned. At baseline, RV systolic and diastolic indices were seriously impaired showing significant improvement at follow-up. RV wall-motion score index during DSE was positively correlated with the same index at follow-up. DSE is a safe and precise modality to predict recovery of stunned myocardium in the setting of RVI.

Comparison of real-time contrast echocardiography and low-dose dobutamine stress echocardiography in predicting the left ventricular functional recovery in patients after acute myocardial infarction under different therapeutic intervention

Background Early prediction of left ventricular (LV) functional recovery after acute myocardial infarction (AMI) remains challenging. This prospective study aims to compare real-time myocardial contrast echocardiography (MCE) with low-dose dobutamine stress echocardiography (LDDSE) in predicting the LV functional recovery in patients after AMI who underwent different therapeutic interventions. Methods Ninety-two patients with AMI were divided into 3 groups: primary coronary intervention group ( n=34), thrombolysis group ( n=30) and conservative therapy group ( n=28). MCE was performed 2.3±0.7 days after chest pain onset. LDDSE was done within 2 days of MCE study. Follow-up echocardiography was performed 4 months later. Results Patients treated by primary coronary intervention or thrombolysis had significantly lower regional perfusion score (0.65±0.53 vs. 1.01±0.49, p=0.008; 0.78±0.55 vs. 1.01±0.49, p=0.03), better contractile reserve (regional dobutamine Δwall motion score -1.12±0.39 vs. −0.80±0.43, p=0.01; −0.99±0.50 vs. −0.80±0.43, p=0.08) and LV function recovery (regional Δwall motion score −1.67±0.53 vs. −1.02±0.46, p=0.003; −1.42±0.58 vs. −1.02±0.46, p=0.03) than those of conservative therapy group. MCE and LDDSE showed good concordance for predicting LV functional recovery (kappa=0.63, p<0.001). Perfusion score index had a good correlation with LV functional recovery ( r=−0.75, p<0.001). Conclusions This study demonstrates that perfusion score index obtained from real-time MCE is comparable to LDDSE in predicting the LV functional recovery even under different therapeutic interventions. Revascularization results in better preservation of myocardial microvascular integrity, regional contractile reserve and LV functional recovery.

Stress-echocardiography in idiopathic dilated cardiomyopathy: instructions for use.

A number of studies have suggested that stress-echocardiography may be used for prognostic stratification in patients with idiopathic dilated cardiomyopathy. There is no consensus on which protocol or which measurements of left ventricular contractile reserve to use. The most frequently used protocol is low-dose dobutamine stress-echocardiography, and most commonly used measures of left ventricular systolic performance are ejection fraction, wall motion score index and cardiac power output.Stress-echocardiography has been shown to predict improvement in cardiac function in patients with recently diagnosed dilated cardiomyopathy, as well as to predict which patients will benefit from the treatment with beta-blockers. Most importantly, stress-echocardiography can identify patients with worse prognosis in terms of cardiac death and need for transplantation. Additionally, contractile reserve is closely correlated with maximal oxygen consumption and can even be used for further stratification in patients with maximal oxygen consumption between 10 and 14 ml/kg/min.Future studies are needed for head-to-head comparison of various protocols in an attempt to make standardization in the assessment of patients with dilated cardiomyopathy.

Predischarge ST Segment and T Wave Patterns in Predicting Left Ventricular Function and Myocardial Viability in Q Wave Anterior Myocardial Infarction Patients

The aim of this study was to investigate the correlation between ECG changes prior to discharge and findings of early low dose dobutamine stress echocardiography (LDSE) performed in 6 +/- 2 days, in patients experiencing their first acute anterior MI. A total of 62 patients admitted with their first acute anterior MI were divided into three groups according to the findings of electrocardiograms performed on the 7-10th days: group A, isoelectric ST and negative or positive T wave; group B, ST elevation (> 0.1 mV) and negative T wave; and group C, ST elevation and positive T wave. There were no significant differences between the groups with respect to thrombolytic therapy and reperfusion criteria. In addition, 90% of the patients in group A (20/22), 66% in group B (12/18, P < 0.05 versus group A), and only 54% in group C (12/22, P < 0.01 versus group A) responded to LDSE. The infarct zone wall motion score index (WMSI) measured by LDSE was significantly decreased in group A compared to basal values (from 2.71 +/- 0.65 to 2.07 +/- 0.71 P = 0.02), and it was significantly different compared to groups B and C. Moreover, the serum creatinine kinase level of the patients in group C was higher (P < 0.01 versus group A), whereas the ejection fraction was inferior (group A 48%, group B 47%, and group C 41%, P = 0.04 versus group A). When the correlations between good left ventricular function and terminal QRS distortion, sum ST elevation, the number of leads with ST elevation, ST elevation shape on admission, and ST and T alterations in ECG at discharge were investigated, an independent correlation was found between ST and T alteration in ECG and a WMSI value < 2 at rest or after LDSE (P = 0.03, OR 3.08, 95%CI 1.05-8.98). At the infarct zone of patients with ST elevation and positive T waves, left ventricular function is worse and the viability is less. This simple classification may be useful in predicting left ventricular function at the time of discharge.

Echocardiography for risk stratification of myocardial infarction in the reperfusion era

The prediction of functional recovery or ventricular remodeling plays a central role in the prognostic assessment of acute myocardial infarction (MI) in the reperfusion era. This article reviews the advances of echocardiographic techniques, focusing on the role of low-dose dobutamine stress echocardiography, contrast echocardiography, transthoracic Doppler of the left anterior descending coronary artery, and transmitral Doppler in detecting myocardial viability and predicting outcome after an acute MI. Moreover, the definition of risk for further ischemic events is another major objective in conservatively managed patients post infarction. As such, the prognostic and economic implication of stress echocardiography compared with that of traditional exercise electrocardiography was considered.

Comparison of real-time myocardial contrast echocardiography for the assessment of myocardial viability with fluorodeoxyglucose-18 positron emission tomography and dobutamine stress echocardiography

Little is known about the diagnostic value of real-time myocardial contrast echocardiography (MCE) for the assessment of myocardial viability. We compared the diagnostic accuracy of MCE with that of low-dose dobutamine stress echocardiography (DSE) and of combined technetium-99 sestamibi single-photon emission computed tomography and fluorodeoxyglucose-18 positron emission tomography and investigated whether quantitative assessment of myocardial blood flow could increase its diagnostic value. Cardiac imaging was performed with these 3 methods in 41 patients who had ischemic heart disease (ejection fraction < 40%) and were being considered for revascularization. Follow-up echocardiograms were obtained after 3 to 6 months in revascularized patients, and increased regional function served as a standard reference for assessment of myocardial viability. A control group of 25 patients who had no coronary artery disease underwent MCE to assess normal values of myocardial perfusion parameters. Recovery of myocardial function was predicted by MCE with a sensitivity of 86% and a specificity of 43%. Nuclear imaging was comparably sensitive (90%) and specific (44%), whereas low-dose DSE was similarly sensitive (83%) but more specific (76%). Normalization of myocardial signal intensity to that of the control group significantly increased the specificity of MCE from 43% to 64% and the accuracy from 73% to 81%. A combination of quantitative MCE and DSE provided the best diagnostic characteristics, with a sensitivity of 96%, a specificity of 63%, and an accuracy of 83%. Thus, MCE is useful for assessing myocardial viability. Normalization of contrast intensity to that of a reference control group is a valid approach for detection of myocardial viability and expands on information obtained from visual MCE and DSE.

DETECTION OF MYOCARDIAL VIABILITY USING DOBUTAMINE STRESS ECHOCARDIOGRAPHY AND MYOCARDIAL CONTRAST AFTER ACUTE MYOCARDIAL INFARCTION

Background: Both low‐dose dobutamine stress echocardiography (LDDE) and myocardial contrast echocardiography (MCE) are capable of identifying myocardial viability by different means. However, it is not well known which of them is more accurate in the setting of AMI. Objective: We evaluated the diagnostic value of LDDE and MCE using second harmonic with and without intermittent imaging in the detection of myocardial viability after acute myocardial infarction (AMI) treated with successful thrombolysis. Methods: We studied 50 patients in the first week after AMI, at rest with LDDE, with and without MCE. We evaluated the recovery of left ventricular ejection fraction (LVEF) at rest by two‐dimensional echocardiography as well as by myocardial scintigraphy (Gated Spect), between the fourth and sixth month of follow‐up. According to an absolute 5% increase in LVEF measured by the two Gated Spect studies, pts were divided in group I, with functional recovery (19 patients) and group II, without functional recovery (31 patients). To analyze the contractility and myocardial perfusion, we used a left ventricular wall motion score index and myocardial perfusion score index at rest and during dobutamine. Myocardial viability was defined by LDDE as an improvement segmental wall motion at least one grade in two or more contiguous infarct zones segments at any stage of dobutamine infusion and by MCE as myocardial perfusion grade 1 or 2 at least in one infarct segment, at any stage of the study. Results: Group 1 had a total of 103 dysfunctioning infarct‐related segments. LDDE revealed the myocardial viability in 61 segments while MCE demonstrated perfusion grade 1 or 2 in 79 of them. In group 2, of 173 dysfunctioning infarct‐related segments, viable myocardium was detected in 23 segments by LDDE and 98 segments by MCE. Only two of 99 segments without viability showed recovery of function at follow‐up. The overall results patient by patient of LDDE in order to predict the LVEF recovery, sensitivity was 95%, specificity 87%, positive predictive value 82%, negative predictive value 96% and diagnostic accuracy 90% (κ= 0.794). When we analyzed the overall results patient by patient of MCE, we demonstrated a sensitivity of 95%, specificity of 52%, positive predictive value of 54%, negative predictive value of 94%, and diagnostic accuracy of 68% (κ= 0.479). Conclusion: The detection of contractile reserve by the use of LDDE was accurate in predicting LVFR in patients after AMI treated with successful thrombolytic therapy, while MCE demonstrated high negative predictive value.

Repetitive dobutamine stress echocardiography for the prediction of anthracycline cardiotoxicity.

To evaluate whether repetitive assessment of systolic and diastolic cardiac function by dobutamine stress echocardiography (DSE) can predict anthracycline cardiotoxicity. Thirty-one patients (age, 57+/-13 years, 22 male) were studied before chemotherapy, with follow-ups during, at the end, and 6 months after chemotherapy. Left ventricular (LV) function was assessed by two-dimensional (2D) echocardiographic wall motion score index (WMSI) and by Doppler echocardiography of mitral valve inflow at rest and during DSE. Radionuclide ventriculography was used as an independent reference for ejection fraction (EF). A reduction of EF >/=5% occurred in 17 patients (group A) at the last follow-up. Patients without decreased EF comprised group B. Early/late diastolic velocity of mitral inflow (E/A ratio) at rest was lower in group A (0.91+/-0.2 vs 1.28+/-0.3, P<0.001), and it was an independent predictor of cardiotoxicity (adjusted for baseline patient characteristics and parameters of systolic and diastolic function). At follow-up, WMSI at rest paralleled radionuclide EF. Contractile reserve at low-dose DSE was preserved in group A. WMSI measured by 2D echocardiography parallels radionuclide EF at follow-up. Assessment of contractile reserve has no incremental value for the early detection of cardiotoxicity. A baseline abnormal E/A ratio is an independent predictor of anthracycline cardiotoxicity.

ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography: Summary Article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to update the 1997 guidelines for the clinical application of echocardiography)

ACC/AHA/ASE 2003 Guideline Update for the Clinical Application of Echocardiography: Summary Article: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to update the 1997 guidelines for the clinical application of echocardiography)

Enoximone very low–dose dobutamine stress echocardiography: a new test for detecting viability in severe myocardial dysfunction after acute myocardial infarction

Relying on the synergistic action on contractility of enoximone and dobutamine when concomitantly infused, 25 patients with their first acute Q-wave anterior myocardial infarctions underwent conventional low-dose dobutamine echocardiography (LDE) and enoximone very–LDE to assess myocardial viability in severely dysfunctioning areas. Images were recorded at peak of pharmacodynamic effect of drugs and 4 months after revascularization. At peak-dose stage of LDE and enoximone very–LDE the regional infarct zone wall-motion score significantly decreased from the basal value of 25.6 ± 2.9 to 16 ± 6.0 ( P < .001) and to 14.5 ± 5.2 ( P < .001), respectively. A high correlation was found by comparing the wall-motion score of each patient calculated at peak effect of combined drug administration with follow-up values ( r s = 0.9). Enoximone very–LDE has proven to be a new test useful to evaluate viability in asynergic segments especially when the results of conventional tests are questionable.

Relationship between myocardial viability and the predischarge electrocardiographic pattern in patients with first anterior wall acute myocardial infarction

Background: The assessment of residual viability in the infarcted area after an acute myocardial infarction is relevant to subsequent management and prognosis. Objective: The aim of this study was to investigate the correlation between myocardial viability after an acute anterior myocardial infarction (AMI) as assessed by low dose dobutamine stress echocardiography (LDDSE) and the electrocardiographic patterns of ST segment and T wave abnormalities at the end of the first week of the acute event. Methods: Sixty-nine consecutive patients (51 men, 18 women, mean age±standard deviation=57±11 years) who admitted to our clinic due to a first episode of transmural AMI were included in this study. Two-dimensional echocardiography was performed to all patients during rest and low dose dobutamine administration at the end of the first week of admission (7±2 days). Patients were classified into four groups according to ST segment and T wave morphology: group A, ST elevation ≤0.1 mV and negative T waves; group B, ST elevation ≤0.1 mV and positive T waves; group C, ST elevation ≥0.1 mV and negative T waves and group D, ST elevation ≥0.1 mV and positive T waves. Results: Myocardial viability was detected more often in patients with isoelectric ST segments (22/24, 92%) than those with elevated ST segments (21/45, 47%) ( P<0.001). Similarly patients with negative T waves had myocardial viability more frequently compared to those with positive T waves (32/45, 71% vs. 11/24, 46%, P<0.01). Seventeen (94%) of 18 patients in group A and 5 (83%) of six patients in group B had viable myocardium ( P>0.05). Myocardial viability was found in 15 (56%) of 27 patients in group C and six (33%) of 18 patients in group D ( P<0.01). As a marker of viable myocardium, isoelectricity of ST segment was specific (92%) but only moderately sensitive (51%), with a 92% positive predictive accuracy and a poor (53%) negative predictive value. T wave negativity was less spesific but more sensitive than isoelectricity of ST segment for myocardial viability. Conclusion: The presence of isoelectric ST segment and negative T wave indicates a high probability of myocardial viablitiy. However, absence of these electrocardiographic patterns does not exclude the presence of viable myocardium.

Quantitative assessment of left ventricular myocardial viability during low dose dobutamine stress echocardiography in combination with color tissue doppler imaging

Quantitative assessment of left ventricular myocardial viability during low dose dobutamine stress echocardiography in combination with color tissue doppler imaging